The primary problems of the sliding electrical contact in an ultra high vacuum environment include cold welding, rapid wear and signal distortion. It is known to prevent the cold welding of sliding electrical contact by the addition of a surface lubricant; however, in instances which life of the operating device must be measured in years, the application of surface lubricants becomes cumbersome, if at all possible. Several self lubricating materials are known in the prior art that possess good lubricating properties and low shear strength. Typical examples are molybdenum disulfide, molybdenum diselenide, tunsten disulfide and graphite. Generally these materials have suitable application methods where low friction characteristics are desired under low stress conditions. However, a long, trouble free life and relatively high loading are frequently required. The high stress conditions induced therby cause frequent failure of the prior materials due to low strength characteristics and inadequate lubrication. With the possible exception of graphite, these prior art self lubricating materials have low tolerance to high temperatures and cannot be used in systems to more than a few hundred degrees Farenheit. Graphite along, amongst these prior art materials, exhibits substantially electrical conductivity but it cannot be used in systems operating in vacuum, since under vacuum conditions the graphite particles become abrasive. It is also known to add high temperature additives, having lubricative properties to a metal matrix; the high temperature lubricants being, for example, aluminum phosphate, barium fluoride and/or calcium fluoride, to form bearing structures. In my prior U.S. Pat. No. 3,755,164, issued Aug. 28, 1973, I disclose a self lubricating bearing of the above description having oxidation resistant, high temperature lubricants including aluminum phosphate, barium fluoride and calcium fluoride dispersed throughout a matrix of silver further including an additive such as aluminum oxide, silicon nitride, or molybdenum silicide. The resulting composition, when pressed and sintered, exhibits good properties for a bearing structure operable at elevated temperatures. However, it has been found that such compositions, while exhibiting relatively good lubricative properties for atmospheric usage at elevated temperatures cannot be utilized in extended life operations under high vacuum conditions due to their rate of wear.